This study was conducted to investigate the effects of various gasification temperatures in a fluidized bed gasifier on biomass-derived products and to evaluate the efficiency of syngas upgraded by a secondary catalytic reactor. The results indicated that biomass vaporization was clearly affected by gasification temperature, resulting in the obtained products having different composition ratios. Additionally, the hydrogen promotion ratios were found to be strongly dependent on the condensable products, indicating that the products were upgraded via the use of a catalyst in the secondary reactor. If biomass vaporized at suitable gasification temperatures can produce a large amount of condensable products, the products could be effectively upgraded for hydrogen production by the secondary catalytic reactor under very mild conditions (250 degrees C). Overall, the process not only upgraded hydrogen production, but also degraded contaminants: therefore, its implementation should reduce the cost of operation and pollution control in the biomass-to-energy industry. (C) 2012 Elsevier Ltd. All rights reserved.